What are the two families that hate each other Romeo an Juliet?

Answer 1

It would be more likely if they actually disclosed it to their families. As it was, no member of their families even knew about it until they were dead.

It is actually apparent that the leaders of the families, Capulet and Montague, would be delighted to make peace. They are not the ones who start the fights. Please note that the fight in Act 1 Scene 1 is caused by the servants of Capulet and Montague, who are not Capulets and Montagues themselves. Tybalt, in particular, is the son of Mrs. Capulet's brother and is not a Capulet himself. Benvolio is a Montague alright but he is trying to stop the fight. Eventually Montague and Capulet get drawn into a fight they didn't start.

In the next scene, Capulet sounds relieved by the Prince's edict, so long as it applies to both families. "But Montague is bound as well as I, in penalty alike, and 'tis not hard, I think, for men so old as we to keep the peace."

Again, in Act 1 Scene 5, it is Tybalt the non-Capulet that wants to fight with Romeo because he is a Montague. Capulet tells him to go to, and that he is a saucy boy for wanting to fight with someone so obviously well-behaved and well spoken of as Romeo. Capulet shows nothing but admiration for Romeo.

In Act 3, Scene 1 we again have a fight breaking out between non-Capulet Tybalt and non-Montague Mercutio, who is actually related to the Prince. He just hangs with the Montagues.

In Romeo's trial, it is Mrs. Capulet who is ranting on about giving Romeo the death penalty for killing Tybalt. Capulet says not a word. Perhaps he is privately thinking "Good riddance" but dares not say so with his wife there.

Finally, in the last Act, more fighting breaks out between Paris and Romeo. Paris is another one of the Prince's kinsmen, another non-Capulet, and insists on fighting Romeo, no matter how Romeo pleads for him to go away and leave him alone.

The Montagues don't figure as much in the story as the Capulets do, but it is worth noting that Rosaline, the girl Romeo is after before he meets Juliet, is in fact Juliet's first cousin on her father's side, and therefore a Capulet. And Romeo's cousin, the Montague Benvolio, thinks this is perfectly OK.

All of this leads me to believe that if Romeo and Juliet had told their parents of their love for each other, their fathers (although perhaps not Juliet's mother) would likely have said, "Great idea! And thank God, it will put an end to this stupid feud!"

Answer 2

The two families that hate each other in "Romeo and Juliet" are the Capulets and the Montagues. They have a long-standing feud that creates tension and conflict throughout the play.

Answer 3

For so long that nobody could remember why they had started the feud in the first place.

Answer 4

It's a tradition. Nobody could remember how it all got started. It was an "ancient grudge".